Viscosity Effect And Structure Optimization Of Turbine Flow Sensor

Turbine flowmeter belongs to speed-type flowmeter and is widely used with theadvantages of high accuracy, good repeatability, wide scale range, light weight andconvenient maintenance. The meter’s performance is greatly affected by the viscosityof the measured medium. The linearity error increases and the reproducibilitydeteriorates with the increasing of the viscosity, which limits its range of applicationgreatly.In this article, the geometric parameters of the turbine flowmeter are optimizedby combining CFD simulations and experiments to reduce the impact of the mediumviscosity on the flowmeter. The main research works of this paper are as follows.Firstly, the research status of the turbine flowmeter and the former researchworks are analyzed. The exiting problems are put forward. All of these studiesestablish the important base for the further research.Secondly, the simulation models of the turbine flowmeter, including theGAMBIT3D geometric models and FLUENT turbulence models are established. Alarge number of different geometric models and turbulence models are studied withCFD simulations. And the best simulation model is determined ultimately bycomparing the results of simulations and experiments.Thirdly, the mechanism of how the medium viscosity impacts on the turbineflowmeter’s performance is analyzed. According to the existing theoretical models,the impact on the performance of the turbine flowmeters with different geometricparameters is studied and the direction of how to optimize the parameters isdetermined preliminarily. On this basis, the turbine flowmeters with differentgeometric parameters are simulated with CFD software strictly in order of theexperimental condition. And the simulation data are analyzed.Fourthly, the turbine flowmeters with fine simulation results are machined intoentities. The corresponding multi-viscosity oil experiments are operated in the sameflow points. The data of experiments and simulation are compared to get thepracticable schemes of how to optimize the turbine flowmeter. The results of theexperiments show that the impact on the turbine flowmeter’s performance by themedium viscosity can be reduced by increasing the impeller tip clearance and theimpeller hub length appropriately. The consistency of the experimental data and simulation results also prove the feasibility of CFD simulation in practicalapplications.